Burnt Flywheel?
Discussion
Anyone suffered this before?
Car was in to get my slave cylinder replaced, while the gearbox etc was off the company checked the clutch area and said my clutch was low (fair enough), the friction surfaces were burnt and that the fly wheel was burnt also. did I want the whole lot replacing? I refused as I know the clutch has plenty left really
but why would I replace the flywheel because its burnt? in fact, why would matter that the flywheel burned? what would this effect?
I don't see it as a problem, once my clutch is replaced (after it dies a death) the new one will wear the scortch marks off, if it hasn't already due to me now having a better biting point - see below.
I also got the old (which i had fitted last october) slave cylinder back and checked it against the original one from my car (pre October 2008) and found that the new cylinder was 5mm longer than the original. Why has this been done in the new design? I dont understand, if the old length worked, why alter it?
Do you think the extra length could have been very slightly pressing the clutch and as its worn has ended up burning the surfaces but not sufficient that I could feel any clutch slip (yet)? when the last slave was in I had a biting point less than 1/4 the way down the travel of the clutch, now I have biting point between 1/4 and 1/2 way (where it should be IMO) since replacing it with my part.
one other point about the "improved" slave is that the inside of th episton no longer sat on the face of the flange, it sat on the slope and created a 5mm gap between the faces. This isn't what i'd class as a very good idea due to the fact that the two parts could have stuck together.
I'm currently trying to get my money (or some) back from the suppliers of the "improved" part as I feel it has prematurly warn my clutch out. (its >10k old the clutch)
Car was in to get my slave cylinder replaced, while the gearbox etc was off the company checked the clutch area and said my clutch was low (fair enough), the friction surfaces were burnt and that the fly wheel was burnt also. did I want the whole lot replacing? I refused as I know the clutch has plenty left really
but why would I replace the flywheel because its burnt? in fact, why would matter that the flywheel burned? what would this effect?I don't see it as a problem, once my clutch is replaced (after it dies a death) the new one will wear the scortch marks off, if it hasn't already due to me now having a better biting point - see below.
I also got the old (which i had fitted last october) slave cylinder back and checked it against the original one from my car (pre October 2008) and found that the new cylinder was 5mm longer than the original. Why has this been done in the new design? I dont understand, if the old length worked, why alter it?
Do you think the extra length could have been very slightly pressing the clutch and as its worn has ended up burning the surfaces but not sufficient that I could feel any clutch slip (yet)? when the last slave was in I had a biting point less than 1/4 the way down the travel of the clutch, now I have biting point between 1/4 and 1/2 way (where it should be IMO) since replacing it with my part.
one other point about the "improved" slave is that the inside of th episton no longer sat on the face of the flange, it sat on the slope and created a 5mm gap between the faces. This isn't what i'd class as a very good idea due to the fact that the two parts could have stuck together.
I'm currently trying to get my money (or some) back from the suppliers of the "improved" part as I feel it has prematurly warn my clutch out. (its >10k old the clutch)
Hi Alan
Yes, but not only was my flywheel burnt it was also badly scored. I too felt no clutch slip prior to this problem being discovered whilst having my top end rebuilt. I was told oil had made its way through one of the 8 bolt holes that hold it to the crank and onto the face of the flywheel. Looking at the clutch itself, it did appear a bit oily as well as the face of the flywheel being blue from heat in places. The clutch had covered 10,000 miles and the plates were down to around 6mm.
What is it with these clutches and their durability? And worse still what is it with the slave cylinders, which seem weaker still.
My original clutch did 16,000 miles, second 10,000 I can only guess what this one's going to do.
Is it just a matter of trying to put 350 or more BHP through a clutch that size causing our problems or is blame shifting towards poor slaves. I've never had a single finger break yet which seems like another common problem.
What should an AP clutch be capable of in a Cerbera under average driving conditions, much more than 16,000 miles, I have no idea?
Regards
Simon
Yes, but not only was my flywheel burnt it was also badly scored. I too felt no clutch slip prior to this problem being discovered whilst having my top end rebuilt. I was told oil had made its way through one of the 8 bolt holes that hold it to the crank and onto the face of the flywheel. Looking at the clutch itself, it did appear a bit oily as well as the face of the flywheel being blue from heat in places. The clutch had covered 10,000 miles and the plates were down to around 6mm.
What is it with these clutches and their durability? And worse still what is it with the slave cylinders, which seem weaker still.
My original clutch did 16,000 miles, second 10,000 I can only guess what this one's going to do.
Is it just a matter of trying to put 350 or more BHP through a clutch that size causing our problems or is blame shifting towards poor slaves. I've never had a single finger break yet which seems like another common problem.
What should an AP clutch be capable of in a Cerbera under average driving conditions, much more than 16,000 miles, I have no idea?
Regards
Simon
Did you replace the flywheel then? fair enough if you did as yours is scored. mine is clear apart from the burnt patches, no oil on it or anything.
I would expect a clutch to last more than 16k regardless of driving style, ok maybe not any style, but certainly more than 10k.
I have been having more thoughts about these "improved" slave cylinders too, how many people have them in their cars and how many know what the difference is? if this is the cause of certain problems people may not know whats causing it.
I think a major problem with the chocolate slave cylinders are the seals, they are s
te! But, I do have to stress that the tolerances between the parts is poor too.
I know some people have had no problems with them, lucky them, but how many have had problem. How many cars are there with these slaves also? do all the speed six engined cars have them?
I would expect a clutch to last more than 16k regardless of driving style, ok maybe not any style, but certainly more than 10k.
I have been having more thoughts about these "improved" slave cylinders too, how many people have them in their cars and how many know what the difference is? if this is the cause of certain problems people may not know whats causing it.
I think a major problem with the chocolate slave cylinders are the seals, they are s
te! But, I do have to stress that the tolerances between the parts is poor too.I know some people have had no problems with them, lucky them, but how many have had problem. How many cars are there with these slaves also? do all the speed six engined cars have them?
WorAl said:
Anyone suffered this before?
Car was in to get my slave cylinder replaced, while the gearbox etc was off the company checked the clutch area and said my clutch was low (fair enough), the friction surfaces were burnt and that the fly wheel was burnt also. did I want the whole lot replacing? I refused as I know the clutch has plenty left really but why would I replace the flywheel because its burnt? in fact, why would matter that the flywheel burned? what would this effect?
I don't see it as a problem, once my clutch is replaced (after it dies a death) the new one will wear the scortch marks off, if it hasn't already due to me now having a better biting point - see below.
I also got the old (which i had fitted last october) slave cylinder back and checked it against the original one from my car (pre October 2008) and found that the new cylinder was 5mm longer than the original. Why has this been done in the new design? I dont understand, if the old length worked, why alter it?
Do you think the extra length could have been very slightly pressing the clutch and as its worn has ended up burning the surfaces but not sufficient that I could feel any clutch slip (yet)? when the last slave was in I had a biting point less than 1/4 the way down the travel of the clutch, now I have biting point between 1/4 and 1/2 way (where it should be IMO) since replacing it with my part.
one other point about the "improved" slave is that the inside of th episton no longer sat on the face of the flange, it sat on the slope and created a 5mm gap between the faces. This isn't what i'd class as a very good idea due to the fact that the two parts could have stuck together.
I'm currently trying to get my money (or some) back from the suppliers of the "improved" part as I feel it has prematurly warn my clutch out. (its >10k old the clutch)
Alreet AlCar was in to get my slave cylinder replaced, while the gearbox etc was off the company checked the clutch area and said my clutch was low (fair enough), the friction surfaces were burnt and that the fly wheel was burnt also. did I want the whole lot replacing? I refused as I know the clutch has plenty left really
but why would I replace the flywheel because its burnt? in fact, why would matter that the flywheel burned? what would this effect?I don't see it as a problem, once my clutch is replaced (after it dies a death) the new one will wear the scortch marks off, if it hasn't already due to me now having a better biting point - see below.
I also got the old (which i had fitted last october) slave cylinder back and checked it against the original one from my car (pre October 2008) and found that the new cylinder was 5mm longer than the original. Why has this been done in the new design? I dont understand, if the old length worked, why alter it?
Do you think the extra length could have been very slightly pressing the clutch and as its worn has ended up burning the surfaces but not sufficient that I could feel any clutch slip (yet)? when the last slave was in I had a biting point less than 1/4 the way down the travel of the clutch, now I have biting point between 1/4 and 1/2 way (where it should be IMO) since replacing it with my part.
one other point about the "improved" slave is that the inside of th episton no longer sat on the face of the flange, it sat on the slope and created a 5mm gap between the faces. This isn't what i'd class as a very good idea due to the fact that the two parts could have stuck together.
I'm currently trying to get my money (or some) back from the suppliers of the "improved" part as I feel it has prematurly warn my clutch out. (its >10k old the clutch)
No expert on this but I must admit I would be a little suspicious of this...maybe its the description 'burnt' that needs clarifying?
If the surface is all scoured and uneven and it would affect the new clutch then fair enough but that doesnt sound like burnt? Is it warped from excessive heat (friction)..?
I know my car has been fitted with the up-rated/up-dated flywheel...something to do with new clutches not being compatible with the original flywheel...just wondering if the SP6 cars are similar and rather than explain properly they have come up with a alternative explanation...? Seems unlikely though...
Where is the car? Anywhere we know?
Hope you get this sorted what will all the effort you have put in with the slave, etc.
Clutch life varies greatly from driver-to-driver so I think you will be unlucky with your attempt at compensation.
The burnt flywheel is a problem I have seen on other vehicles. The burning is not usually even and will lead to cracks and distortion eventually. The surface will go through different heat cycles and areas become glazed with differing levels of grip for the clutch plate. Sometimes skimming can alleviate the effects but the only cure is replacement.
The burnt flywheel is a problem I have seen on other vehicles. The burning is not usually even and will lead to cracks and distortion eventually. The surface will go through different heat cycles and areas become glazed with differing levels of grip for the clutch plate. Sometimes skimming can alleviate the effects but the only cure is replacement.
peteA said:
WorAl said:
Anyone suffered this before?
Car was in to get my slave cylinder replaced, while the gearbox etc was off the company checked the clutch area and said my clutch was low (fair enough), the friction surfaces were burnt and that the fly wheel was burnt also. did I want the whole lot replacing? I refused as I know the clutch has plenty left really but why would I replace the flywheel because its burnt? in fact, why would matter that the flywheel burned? what would this effect?
I don't see it as a problem, once my clutch is replaced (after it dies a death) the new one will wear the scortch marks off, if it hasn't already due to me now having a better biting point - see below.
I also got the old (which i had fitted last october) slave cylinder back and checked it against the original one from my car (pre October 2008) and found that the new cylinder was 5mm longer than the original. Why has this been done in the new design? I dont understand, if the old length worked, why alter it?
Do you think the extra length could have been very slightly pressing the clutch and as its worn has ended up burning the surfaces but not sufficient that I could feel any clutch slip (yet)? when the last slave was in I had a biting point less than 1/4 the way down the travel of the clutch, now I have biting point between 1/4 and 1/2 way (where it should be IMO) since replacing it with my part.
one other point about the "improved" slave is that the inside of th episton no longer sat on the face of the flange, it sat on the slope and created a 5mm gap between the faces. This isn't what i'd class as a very good idea due to the fact that the two parts could have stuck together.
I'm currently trying to get my money (or some) back from the suppliers of the "improved" part as I feel it has prematurly warn my clutch out. (its >10k old the clutch)
Alreet AlCar was in to get my slave cylinder replaced, while the gearbox etc was off the company checked the clutch area and said my clutch was low (fair enough), the friction surfaces were burnt and that the fly wheel was burnt also. did I want the whole lot replacing? I refused as I know the clutch has plenty left really
but why would I replace the flywheel because its burnt? in fact, why would matter that the flywheel burned? what would this effect?I don't see it as a problem, once my clutch is replaced (after it dies a death) the new one will wear the scortch marks off, if it hasn't already due to me now having a better biting point - see below.
I also got the old (which i had fitted last october) slave cylinder back and checked it against the original one from my car (pre October 2008) and found that the new cylinder was 5mm longer than the original. Why has this been done in the new design? I dont understand, if the old length worked, why alter it?
Do you think the extra length could have been very slightly pressing the clutch and as its worn has ended up burning the surfaces but not sufficient that I could feel any clutch slip (yet)? when the last slave was in I had a biting point less than 1/4 the way down the travel of the clutch, now I have biting point between 1/4 and 1/2 way (where it should be IMO) since replacing it with my part.
one other point about the "improved" slave is that the inside of th episton no longer sat on the face of the flange, it sat on the slope and created a 5mm gap between the faces. This isn't what i'd class as a very good idea due to the fact that the two parts could have stuck together.
I'm currently trying to get my money (or some) back from the suppliers of the "improved" part as I feel it has prematurly warn my clutch out. (its >10k old the clutch)
No expert on this but I must admit I would be a little suspicious of this...maybe its the description 'burnt' that needs clarifying?
If the surface is all scoured and uneven and it would affect the new clutch then fair enough but that doesnt sound like burnt? Is it warped from excessive heat (friction)..?
I know my car has been fitted with the up-rated/up-dated flywheel...something to do with new clutches not being compatible with the original flywheel...just wondering if the SP6 cars are similar and rather than explain properly they have come up with a alternative explanation...? Seems unlikely though...
Where is the car? Anywhere we know?
Hope you get this sorted what will all the effort you have put in with the slave, etc.
The description he gave was similar to that of Storers, just dont get it when its not all that old, whole engine, clutch flywheel was replaced circa 10k ago. Its not warped or warn, just had burnt patches. Will leave it and see, not too concerned as will replace clutch when it needs it, just not replacing it if its still working fine, which it is.
The car was in at Hexham so I have no doubt that he was telling me the truth, i trust them with my car, was asking more about the case with the slave as I can see a different length being a problem
Edited by WorAl on Wednesday 11th November 09:31
WorAl said:
Did you replace the flywheel then? fair enough if you did as yours is scored. mine is clear apart from the burnt patches, no oil on it or anything.
Yes I had one of those Raceproved superlight steel billet ones fitted along with a new AP clutch and new slave.Regards
Simon
Edited by SimonKD on Wednesday 11th November 09:38
Is the burning symmetrical? IE even placement around the flyhweel or is it grouped? My multiplate "burned" in several sections of the flyhweel, the cover plate and the floater. It ended up that Kennedy (it's not a Cerb) didn't grind the cover after riveting the fingers to it. The rivets had pulled the cover plate not flat in certain spots, hence overload in spots.
I suspect by the number of finger failures that the clutch in the Cerb is over actuated. This will damage the spring loading of the fingers, cause asymetric loading of the plates consequently "burning" in spots.
The other option is the compound of the plates. The material on my twin puck clutch is so agressive that I can generally see every gearchange with a spot on the flywheel, floater and cover plate.
I suspect by the number of finger failures that the clutch in the Cerb is over actuated. This will damage the spring loading of the fingers, cause asymetric loading of the plates consequently "burning" in spots.
The other option is the compound of the plates. The material on my twin puck clutch is so agressive that I can generally see every gearchange with a spot on the flywheel, floater and cover plate.
SimonKD said:
Mine was burnt in symetrical rings running all the way around the flywheel face. They are dark blue. Pics not very good.
Regards
Simon
From what I gather with mine, is that it has burnt in patches, not in rings like that? but i may have miss understood, will give them a call later and see what they say.Regards
Simon
Aren't they trying to save you money by replacing worn bits now while they have it apart? If you have to take it apart again later on you're going to pay all those labour costs again, so it makes sense t replace anything marginal now.
If you don't trust that they're telling you the truth and giving you sound advice, they shouldn't be working on the car in the first place.
If you don't trust that they're telling you the truth and giving you sound advice, they shouldn't be working on the car in the first place.
GreenV8S said:
Aren't they trying to save you money by replacing worn bits now while they have it apart? If you have to take it apart again later on you're going to pay all those labour costs again, so it makes sense t replace anything marginal now.
If you don't trust that they're telling you the truth and giving you sound advice, they shouldn't be working on the car in the first place.
No i do trust what they were saying and don't for one second believe that my clutch will last another 5k miles (i hope it will though), was just questioning the fact of replacing the flywheel because its burnt (never heard of this before) and I couldnt afford the extra £1200 for the clutch/flywheel right now, hopefully it will last until MOT/service time and I will replace it then.If you don't trust that they're telling you the truth and giving you sound advice, they shouldn't be working on the car in the first place.
But it has also come to light that the slave will be pushing my clutch permanently so the burninig could be caused by that.
Just looking for opinions.
Dave 500 said:
How long do the clutches in Cerbera's generally last?
Mines on 45000 and still original
No way could I put up with replacing it every 10000 miles.
good stuff Mines on 45000 and still original
No way could I put up with replacing it every 10000 miles.
(you certain of that though?)I would expect a clutch like these in a car like these to last 20-25k to be honest but it doesn't seem to be happening.
There is an important point made in the OP`s opening post about the slave piston being 5m/m longer....its the wrong slave cylinder!!!
I know this from personal experience.
My slave seals went,i bought a new slave cylinder & seals & fitted it with the original clutch,when i drove the car the clutch slipped(it didn`t originally).I went back to the supplier of the slave for advice & was told thet Cerbs were fitted with 3 different slave cylinders and the one they had sold me was incorrect,the piston was 5m/m longer than my original one!
They had to modify one for me as the one fitted to my car wasn`t available,i fitted this & hey presto!~no issues.
So its possible that this is whats happened with yours?
By the way,no-one appears to know which particular slave was fitted to which car,so always take the old one with you to ensure the new one is IDENTICAL!!!.
I know this from personal experience.
My slave seals went,i bought a new slave cylinder & seals & fitted it with the original clutch,when i drove the car the clutch slipped(it didn`t originally).I went back to the supplier of the slave for advice & was told thet Cerbs were fitted with 3 different slave cylinders and the one they had sold me was incorrect,the piston was 5m/m longer than my original one!
They had to modify one for me as the one fitted to my car wasn`t available,i fitted this & hey presto!~no issues.
So its possible that this is whats happened with yours?
By the way,no-one appears to know which particular slave was fitted to which car,so always take the old one with you to ensure the new one is IDENTICAL!!!.
The slave cylinder and clutch variations are well documented for cerberas, I'm surprised anyone investigating clutch and slave options still falls foul of this. It's all well known about since around 1998 when the changes first occurred from early clutch to late clutch. But also anyone working on TVRs knows there's product variation over production runs, if they don't check that the part going in is identical in important dimensions (as mentioned above) then they are foolish.
There was a case of a distributor of parts selling early (long) slave cylinders to everyone and anyone and then offering to reduce the length after they'd got the part fitted and it didn't work .. why they didn't explain this lengt difference to the customer at point of sale I'll never know.. it is barmy beyond belief .. it must have created a whole load of hassle for everyone concerned including the parts seller. Though I say it again : the changes are well known and well documented so anyone fitting a long slave with a deep clutch pack really hasn't done their homework.
There was a case of a distributor of parts selling early (long) slave cylinders to everyone and anyone and then offering to reduce the length after they'd got the part fitted and it didn't work .. why they didn't explain this lengt difference to the customer at point of sale I'll never know.. it is barmy beyond belief .. it must have created a whole load of hassle for everyone concerned including the parts seller. Though I say it again : the changes are well known and well documented so anyone fitting a long slave with a deep clutch pack really hasn't done their homework.
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